Sorry, wall of text.
I feel that a lot of photography isn’t so much which camera to get, but in knowing how to use it and manipulate it to get the look you want. Like sam_sneed said if you don’t know what you’re doing, or just shooting in AUTO all your pictures will look like they came from a point and shoot. Along with knowing how to manipulate your camera, being able to see things creatively and being able to visualize what kind of composition you want will make the biggest difference. I would pick up a photography book or two. I liked Bryan Peterson’s Understanding Exposure as to the basics on how your camera and lenses work.
As far as equipment goes I would say lens choice is more important than the camera body itself. All the prices I’ll list are for Nikon lenses and from B and H Photography.
For portraits, or shooting photos of the kids around the house, I use a 50mm f/1.4. You can would definitely go with a 50mm f/1.8 since The f/1.8 is cheaper and considering I rarely go below f/2.0 you could get away with that.
A fixed lens isn’t very good for landscape photography though. For that you could get away with an 18-55mm f/3.5-5.6 ($99) and a 55-200mm f/4-5.6 ($150-250, depending on if you want vibration reduction). That’s what I’ve used, I do find it gets irritating having to switch lenses all the time so an 18-200mm lens would would make it easier but runs $850.
As far as the camera goes, I’m partial to Nikon. Mainly it’s because it was what I was familiar with since it is what we use at work, and reviews, I had read at the time I bought my camera, suggested that their lenses are better. Between the D3100, D3200 or the D5100… I don’t have a strong preference either way. The D3200 does have 8 MP more and apparently has a Guide Mode that tells you how to set the camera for whatever picture type you are trying to take, which might help, but it would probably take less time to read a photography book.
Thanks, the D3200 seems a bit out of my price range.
I can pick up a new D3100 for $380 or a new D5100 for $455
the 5100 seems to outperform picture quality wise, but not sure I want to risk the shutter issue.